The present invention relates to industrial fastners and more particularly to those industrial fasteners which are used to removably secure two panels.
At the present time there are a number of industrial fasteners commercially available to secure two panels, and many types of such fasteners have been proposed in prior patents. The panels may be, for example, flush mounted machine service or enclosure panels which are to be readily opened and closed. The fastener of the present invention is particularly well suited for assembling curved sheets such as engine cowlings, flat sheets such as access panels, and accommodating slightly misaligned holes in the two panels to be joined.
Generally, industrial fasteners of this general type consist of two separated members each one of which is attached to one of the panels. For example, one panel may be the machine wall or frame and the other may be the service or enclosure panel. Such fasteners may be used to obtain tight seals while allowing for quick access. Frequently, such fasteners are locked by a 90.degree. turn and unlocked by a 90.degree. turn in the opposite direction.
Such two-member fasteners may be generally classified to be of one of two types. The first is a spring socket type wherein the receptacle grips and exerts a tension on the stud member, as is disclosed in U.S. Pat. No. 2,200,702 to Oddie; U.S. Pat. No. 2,250,072 to Tinnerman; U.S. Pat. No. 2,413,510 to Luce; U.S. Pat. No. 2,334,676 to Jones; and U.S. Pat. No. 2,589,028 to Poupitch. Similarly, U.S. Pat. No. 3,900,931 to Lavoillotte discloses a ramped receptacle tensioning member.
An alternative general type of fastener, illustrated by U.S. Pat. No. 2,486,411 to Huelster; U.S. Pat. No. 3,136,017 to Preziosi; U.S. Pat. No. 2,975,667 to Bross; U.S. Pat. No. 3,675,280 to Winslade and U.S. Pat. No. 2,884,667 to Zahodiakin, discloses spring-loaded stud members. However, these above-mentioned spring-loaded stud fastener patents all also include spring retaining housings and all but the Preziosi patent require the lateral stud projections to transverse a ramped receptacle for fastener tightening. Although the Preziosi patent relies on the spring stud for tensioning the receptacle member, that stud comprises two plate members.
It has also been suggested that the turn member of an industrial fastener may be stamped from sheet stock, as in U.S. Pat. Nos. 3,900,931 and 2,593,064, or may be formed as a flat member as in U.S. Pat. No. 2,334,676.
The presently commercially available fasteners have been found satisfactory for many purposes. However, there is a need for a rugged, easily operable, not overly complex or expensive fastener which may be made from relatively low cost materials without relatively expensive machining or other relatively costly manufacturing operations.